It makes sense.
Why would any Gov employee access a hacker site from a secure network?
The pipe works two ways.
While WAPO is probably safe Wikileaks is probably not.
DSS sent out emails to contractors saying individuals carrying clearances were not allowed to access classified information from contractor’s equipment that were posted on news site such as the Guardian. We have been told that wikileaks was off limits on work or home computers.
If you carry a clearance you not allowed to access classified information if you do not have a need to know.